One-Pot Transition-Metal-Free Synthesis of π-Extended Bipolar Polyaromatic Hydrocarbons.

The development of straightforward synthetic methods for photoactive polycyclic aromatic hydrocarbons (PAHs) that avoid Pd-catalyzed or radical-based processes remains a challenge. Such methods are essential to reducing the cost and environmental impact of organic photodevices. In this work, we present a one-pot synthetic approach for creating novel bipolar PAHs with extended π-conjugation, which are not accessible via conventional Pd-catalyzed routes.

Intermolecular interaction energies with AROFRAG-A systematic approach for fragmentation of aromatic molecules.

Intermolecular interactions with polycyclic aromatic hydrocarbons (PAHs) represent an important area of physisorption studies. These investigations are often hampered by a size of interacting PAHs, which makes the calculation prohibitively expensive. Therefore, methods designed to deal with large molecules could be helpful to reduce the computational costs of such studies.

AROFRAG─A Systematic Approach for Fragmentation of Aromatic Molecules.

We present a new systematic fragmentation scheme of polycyclic aromatic hydrocarbons (PAHs), including fullerenes and nanotubes, based on an idea to treat a sextet ring as a single unbreakable unit so that the basic unit of aromaticity remains preserved upon fragmentation. In the approach, denoted as AROFRAG (from aromatic fragmentation), a set of predefined elementary subsystems, such as naphthalene and biphenyl in the first model and larger PAHs in the second and third models, is generated with appropriate weights with the aim of reproducing the structure of the original molecule. The energies of the molecules are approximated as weighted sums of the energies of these subsystems.

Association Complexes of Calix[6]arenes with Amino Acids Explained by Energy-Partitioning Methods.

Intermolecular complexes with calixarenes are intriguing because of multiple possibilities of noncovalent binding for both polar and nonpolar molecules, including docking in the calixarene cavity. In this contribution calix[6]arenes interacting with amino acids are studied with an additional aim to show that tools such as symmetry-adapted perturbation theory (SAPT), functional-group SAPT (F-SAPT), and systematic molecular fragmentation (SMF) methods may provide explanations for different numbers of noncovalent bonds and of their varying strength for various calixarene conformers and guest molecules. The partitioning of the interaction energy provides an easy way to identify hydrogen bonds, including those with unconventional hydrogen acceptors, as well as other noncovalent bonds, and to find repulsive destabilizing interactions between functional groups.